A new study finds that preschool classrooms — those in which teachers provide “high doses” of activities “emphasizing language, preliteracy and math concepts” — give “positive” academic benefits to children as measured by standardized tests, and that black students generally get a bigger boost than others. Think flashcards.

The issue of academic “rigor” in the early years of a child’s education has been a part of the education reform debate for years. Every now and then, there is a study that shows that kids do better on tests by some number of weeks or months if they go to an academic kindergarten, though tests are hardly the best indicator for how well children are developing, and the gains that are cited are short-lived.

We have decades of research in child development and neuroscience that tell us that young children learn actively — they have to move, use their senses, get their hands on things, interact with other kids and teachers, create, invent. But in this twisted time, young children starting public pre-K at the age of 4 are expected to learn through “rigorous instruction.”

And never in my wildest dreams could I have imagined that we would have to defend children’s right to play.